Slotting machine



Jan. 10, 1933. E. B. STRMPSON SLOTTING MACHINE Filed Dec. 17, 1929 7Sheets-Sheet 1 INVENTOR Edam/252% i7 Jfli M ATTORNEY Jan. 10, 1933. E.B. STIMPSON SLOTTING MACHINE Filed Dec. 17, 1929 7 Sheets-Sheet 2 millll INVENTOR EJ50 172 B v St Z/zmm BY v r 10, 1933. E. B. STIMPSON.1,893,509

SLOTTING MACHINE Filed Dec. 17. 1929 7 Sheets-Sheet s Him...

INVENTOR Jan. If 1933. B, STIMPSQN 1,893,509

SLOTTING MACHINE Filed Dec. 17. 1929 7 Sheets-Sheet 4 INVENTOR B.lfilizpmi M ORNEY Jan. 10, 1933. s-n psoN 1,893,509

SLOTTING MACHINE Filed Dec. 17. 1929 T'Sheets-Sheet 5 IN ENTOR SLOTTINGMACHINE Filed Dec. 17. 1929 7 Sheets-Sheet 6 INVENTOR- M TTORNEY Jan.10, 1933. STIMPSON 1,893,509

SLOTTING MACHINE Filed Dec. 17, 1929 7 Sheets-Sheet 7 INVENTOR M ORNEYPatented Jan. 10, 1933 UNITED Y STATES EIDXVIN B. STIMPSON, 0F BROOKLYN,NEW YORK, ASSIGNOR T0 EDWIN B. STIMPSON PATENT OFFICE COMPANY, OFBROOKLYN, NEW YORK, A. CORPORATION OF NEW YORK SLOTTING MACHINEApplication filed December 17, 1929. Serial No. 414,637.

This invention relates to the slotting of blanks and will be disclosedin connection with a machine for cutting slots in rivet blanks tothereby make bifurcated rivets. The invention is, however, applicable tothe slotting of blanks for other purposes.

Heretofore in the art cut bifurcated rivets have usually been made bysuccessively feeding rivet blanks into cutting position where they aresuccessively slotted by a rotating saw or cutter. There is a practicallimit to the speed at which the saw teeth can be satisfactorily driventhrough the rivet blank, and this places a definite limit on the speedof operation of the machine. Attempts have been made to speed upproduction by successively feeding two rivets during each rotation ofthe cutter head and providing the cutter head with two saws o1" cutterspositioned diametrically opposite one another to slot the two rivetblanks successively. See patent to Haven-er No. 1,588,57 6. Theseattempts to speed up production have not been altogether satisfactory,partly because of the difliculty of carrying out (in the types ofmachines used) the rivet feeding and removing operations with therequired rapidity.

In the operation of a slotting machine at high speed, the saws orcutters wear rapidly and hence the machine has to be frequently shutdown to replace the cutters. With the constructions of the prior artthis replacing of cutters takes considerable time because the freshcutters have to be accurately shimmed up and located on the machinewhile it is shut down. Accordingly, with the prior art machinesconsiderable production time is lost in the changing of cutters.

The general object of the present invention is to provide a method ofand/or a machine for slotting blanks at a high rate of speed.

Another object of the invention is to provide a slotting machine capableof operation at a high rate of speed without frequentshut downs foradjustments or replacements of parts.

Another object of the invention is to provide a slotting machine inwhich shimming up of replacement cutters may be effected prior to theshutting down of the machine to make the actual replacement of thecutters.

Other objects of the invention will be obvious from the followingdisclosures.

The invention is disclosed in connection with a machine which operatesas follows: Rivet blanks to be slotted are automatically fed to a dialhaving a series ofblank receiving recesses. This dial is rotatedstepby-step, and at each step a new blank is fed to the dial. Atalternate steps of the dial two blanks carried by the dial are clampedfor slotting and are simultaneously slotted by a pair of saws or cutterscarried by a rotating cutter head. The two saws or cutters are mountedupon a cutter holder which in turn is detachably mounted on the rotatingcutter head. Fresh saws may be shimmed up in position upon a sparecutterholder, and when the machine is shut down for an interchange of saws itis only necessary to remove the cutter holder (with its saws) as a unit,and replace it with the spare cutter holder on which saws have beenpreviously shimmed up and mounted.

Fig. 1 of the drawings is a plan View of the machine, showing certainparts broken away.

Fig. 2 is an end elevation of the machine showing the cover plateremoved from the cutter chamber and various parts of the machine brokenaway or in section.

Fig. 3 is a side elevation of the machine with a portion of the frameshown as broken away.

Fig. 4 is a fragmentary perspective view showing the rotating dial andcertain parts associated therewith.

Fig. 5 is a perspective view showing the clamps for clamping the shanksof the rivet mately on line 19-19 of Fig. 1, showing more removing chipsfrom the cutters.

blanks when the blanks are in cutting position.

Fig. 6 is a detail plan view showing the clamping of the rivet shankswhen the blanks are in cut-ting position.

Fig. 7 is a detail sectional view taken on line 7-7 of Fig. 4 showingprimarily the clamping of the heads of the rivets when the blanks are incutting position.

Fig. 8 is a detail view of the cutter head, etc., taken on line 8-8 ofFig. 9.

Fig. 9 is a sectional view of the cutter head, etc., taken on line 99 ofFig. 8.

Fig. 10 is a detail plan view of the cutter head, etc.

Fig. 11 is a detail elevational view showing more or lessdiagrammatically the preferred arrangement of the cutters, with blanksin cutting position.

Fig. 12 is a detail plan view showing more or less diagrammatically thepreferred arrangement of the cutters, with blanks in cutting position. Y

Fig. 13 is a detail elevational View showing more or lessdiagrammatically an alternative arrangement of the cutters, with blanksin cutting position.

Fig. 14 is a detail plan view taken on line 1414 of Fig. 13-.

Fig. 15 is a detail plan view showing clamps for clamping the rivetblanks in the position shown in Figs. 13 and 14.

Fig. 16 is a detail View, taken on line 1616 of Fig. 3, showing more orless diagrammatically the mechanism for retracting the spring pressedclamp which clamps the heads of the rivets while they are being slotted.

Fig. 17 is a detail view, taken on line 1717 of Fig. 3, showing more orless diagrammatically the mechanism for positively positioning one ofthe dies which clamps the shanks of the rivets while they are beingslotted.

Fig. 18 is a detail view, taken on line 18-18 of Fig. 3, showing more orless diagrammatically the mechanism for retracting the other die (aspring pressed die) which clamps the shanks of the rivets while they arebeing slotted.

Fig. 19 is a detail View taken approxior less diagrammatically themechanism for feeding the rivet blanks to the dial.

Fig. 20 is a fragmentary detail view, taken on line 20-20 of Fig. 2,showing brushes for General organization of the machine Reference willnow be had to Figs. 1, 2, and 3. The frame of the machine 1 hasjournaled therein a main shaft 2 and a secondary shaft 4, each of theseshafts being mounted in any suitable manner that will prevent end play.One end of the main shaft 2 carries a cutter head 5 and the other endcarries agear 6 meshing with a gear 7 on secondary shaft 4. Gear 6 hastwice the pitch diameter of gear 7, so that the secondary shaft 4 makestwo complete rotations for each rotation of the main shaft 2. Themachine is driven from any suitable source of power such as a belt 8from which motion is transmitted to a gear 9 meshing with gear 6.

Mounted on the top of the frame of the machine is a stationary tubularhead 10 (see also Fig. 4) within which there is a rotatable stub shaft11 adapted to be driven by a worm gear 12 secured in any suitable mannerto the upper end of the stub shaft 11. The lower end of the stub shaft11 has an enlarged portion 14 to which there is secured in any suitablemanner a disc 15 having a series of equally spaced recesses adapted toreceive rivet blanks. This disc 15 is usually called a dial.

Meshing with the worm gear 12 there is a worm cam 13 carried by thesecondary shaft 4. As shown in Fig. 1, the thread of the worm cam 13 hasa straight portion which extends for nearly a half circumference and aninclined portion which extends for the re mainder of the circumference.Accordingly, as the secondary shaft 4 rotates, the worm gear 12 and thedial 15 will be advanced in a step-by-step manner, being held stationaryfor nearly a half of each complete rotation of the shaft 4. As shown inFigs. 1 and 2, the ends of the worm thread overlap slightly andpreferably this overlap is positioned at the trailing end of thestraight portion of the 1 thread ofthe worm.

Rivet feeding meciz am'sm Rivet blanks slide down an inclined raceway20, as shown in Fig. 1. In practice the blanks are usually dumped inbulk into a hopper, with which there is associated mechanism to arrangethe blanks and deliver them in proper position to the race-way 20. Suchhopper mechanisms are well known in the art and form no part of thepresent invention and hence are not herein disclosed. It may be pointedout, however, that it is usually necessary to have somesource of powerto actuatethe hopper mechanism and this power may be furnished eitherfrom an eccentric 21 or a grooved pulley 22 carried on the secondaryshaft 4.

At each period of rest of the dial 15, cam 24 on shaft 4 releases rockshaft (see Fig. 19) and allows spring 26 to move slide 27 to the left,thus feeding a rivet blank into a recess in the dial 15 which ispositioned to re ceive the blank. After the rivet has been fed to thedial, cam 24 returns the rock shaft 25 and its associated parts to theposition shown in Fig. 19, this return movement being carried outagainst the force exerted by spring Rivet clamping mechanism Atalternate periods of rest of the dial 15, two rivet blanks carried bythe dial are clamped for slotting. The shanks are clamped by two opposedslides or dies and 81 (Fig. which are positioned transversely of themain shaft 2 and the clamping ends of which slide beneath the edge ofthe dial 15, as shown in Figs. 4 and 6. The slides 30 and 81 areprovided with arcuate slots 32 through which the saws pass to slot theshanks of the rivets. The clamping end of the slide 31 is pivoted at 33to permit a slight sidewise swing which facilitates firm clamping of thetwo rivet shanks in cases where the shank of one rivet to be clamped isslightly larger than the shank of the other rivet to be clamp-ed.Preferably this pivotal connection is sufficiently loose to permitslight vertical tipping of the end of slide 31 to enable it to conformto rivet shanks which may be slightly tapered.

The slide or die 80 is positively positioned to clamp the shanks of therivets, and is spring retracted from the shanks of the rivets after therivets have been slotted. Mounted on the main shaft 2 there is a cam 35(Figs. 1 and 17 which actuates a cam lever 36 that is adapted to pressinwardly the free end of another lever 37 (Fig. 1) pivoted at 38. Thelever 37 bears against the end of slide 80 (Fig. thus moving the slide30 into pos1- tion to clamp the shanks of the rivets. When the cam 35releases the cam lever 36 and associated parts, spring 89 (Figs. 2 and5) retracts the slide or die 80 from its clamping position. In actualpractice this back and forth clamping movement of slide 80 is usuallyonly a small fraction of an inch.

Die 81 is biased into clamping position by a strong spring 40 (Figs. 1and 2), but normally the die is held out of clamping position by cam 41(Figs. 1 and 18) carried by shaft 2. When the cam 41 comes to theposition shown in Fig. 18 it allows cam lever 44 to descend, therebypermitting motion of rock shaft 45 to release the die 31 and permit itto be moved into clamping position by spring 46. hen the slotting of theclamped rivets has been completed, cam 41 will raise cam lever 44, thusreturning slide 81 to its nonclamping position.

The heads of the rivets are clamped by a clamp block 46 (see 4 and 7)pivoted at 47 to the end of a lever 50. The lever 50 is pivotallymounted at 51 and biased by strong springs 52 (Figs. 1 and to urge itinto clamping position. However, the lever 50 is normally held innon-clamping position by a bent cam lever 54 16) the horizontal arm ofwhich is held in depressed position by a cam 55 on the main shaft 2.When the rivets are to be clamped cam 55 releases cam lever thuspermitting the springs 52 to elevate one end of lever 50 and press theclamp block 46 (Fig. 4) against the heads of the rivets. After therivets have been slotted cam 55 effects the return of clamping lever 50and clamp block 46 to non-clamping position. In order to prevent lostmotion and to keep the end of the horizontal arm of cam lever 54 frommoving out of engagement with lever 50 a small spring 56 is provided.

Gutter head and cutters The mechanical construction of the cutter headand cutters is best shown in Figs. 8, 9, and 10. One end of the mainshaft 2 carries a cutter head 5 which is preferably forged integral withthe main shaft. Detachably mounted on the cutter head is a cutterholder, designated as a whole by 61, carrying a pair of toothed cuttersor saws 64 and 65. The cutter holder comprises a base 66 from the centerof which projects an upstanding partition portion 67 against which thecutters 64 and are clamped by means of blocks 68 and 69. The blocks 68and 69 are held against the cutters by three bolts 70, 71, and 72. Bolt70 passes through the blocks 68 and 69, through elongated holes in eachof the cutters 64 and 65, and through the partition member 67, as shownin the drawings. Bolts 71 and 72 pass through the base 66 of the cutterholder and. hold pairs of clamps 73, 7 3 'and 74, 74 respectivelyagainst the outer surfaces of the blocks 68 and 69. These clamps havelower inwardly projecting ends as at 76, 7 6 which engage legs 77 and 78that depend from the base 66 of the cutter holder. The clamps held bythe bolts 71 and 72 also have inwardly projecting upper ends as at 79and 79 so that a strong clamping pressure is exerted near the upperedges of the clamp blocks 68 and 69. The endwise position of the cuttersis determined by end plates 80 and 81 which may be permanently screwedto the ends of the partition member 67.

The cutter holder 66 is accurately located on the cutter head 5 by anysuitable means such as dowel pins 86 and 87 and is secured in place byany suitable means such as bolts 84 and 85. As the cutters wear and haveto be sharpened, it is necessary to shim them up so that they willcontinue to cut the same depth of slot in the rivet blanks. The cutterholder 61 and its cutters may be removed from the cutter head as a unit,and replaced by a similar unit in which the cutters have previously beenshimmed up. Thus the shimming operation can be done on spare partsbefore themachine is stopped for the insertion of the'new cutters. Thisinterchange of cutter holder units can be done Very quickly, thusminimizing shut down time to change cutters. I

Preferably, the cutters 64 and 65 are arranged so that the teeth arestaggered, as shown in Figs. 11 and 12. By this arrangement chips arecut alternately from a pair of clamped rivets 90 and 91, thus minimizingvibration from the cutting operation. This staggered arrangement of theteeth of the cutters can be produced by having the teeth on one cuttercut slightly in advance of the teeth on the other cutter. However, it isusually preferable to manufacture the cutters as duplicates and producethe staggering of the teeth by mounting one cutter slightly in advanceof the other, rotatively speaking. Accordingly, the cutter receivingseats of the cutter holder 61 are preferably so arranged that one saw ispositioned slightly in advance of the other saw.

The invention contemplates the use of more than two cutters positionedside by side on the cutter head, two cutters being shown merely by wayof illustration. WV here more than two cutters are used side by side, itis desirable also to so arrange the cutters that two teeth (of differentcutters) do not enter the rivets at the same time. In other words, thecutters are preferably so arranged as to place the corresponding teethof the various cutters in echelon, whether there be two cutters or morethan two.

Alternative arrangement of cutters As an alternative to positioning thecutter teeth in echelon as shown in Figs. 11 and 12, the cutters 64 and65 may be mounted with respective teeth in alignment, as shown in Figs.13 and 14, with the rivets to be cut, 90 and 91 positioned so that chipsare cut first from one rivet and then from the other rivet. The rivetreceiving recesses in the dial 15 are of such depth that one rivet canbe shifted slightly toward the center of the dial and the other rivetshifted slightly toward the circumference of the dial, when the rivetsare clamped for slotting. In this case, the shank clamps for the rivetsmay be as shown in F 15 in which is the positively positioned die and 31the spring pressed die. In clamping the rivets the shank clamps thenstagger the rivets by an amount equal to half the distance between theteeth on the cutters,

, one rivet being shifted inwardly of its normal block 5 position online 93 and the other rivet being shifted outwardly.

Rice? discharge mechanism As the rivets are carried around they hang bytheir heads from disc 15 with their shanks traveling in an arcuatepassageway between stationary frame portion 57 (Fig. 4) and otherstationary parts of the machine such as (Fig. 1). This arcuatepassageway terminates with block 58 and the shanks of the slotted rivetssoon engage stationary cam 59 which removes the finished rivets from thedial and permits them to fall into a discharge chute (not shown).Screwed to stationary head 10 there is a block 60 having in tegraltherewith a stationary cam 62 adjacent rotating section 14 and the uppersurface of disc 15. This cam 62 acts to eject from disc 15 anything thatmay be lying on top of it such as a rivet head from which the shank hasbeen broken.

Removal of chips from the cutters In actual practice the machine inoperation is provided with a cover which lies against the rim 94 (Fig.2) and seals oii the cutter chamber to permit the forcing oflubricantover the cutters to lubricate the cutters and remove the chipstherefrom. Means for so lubricating the cutters are old in the art andform no part of the present invention. Accordingly, they are omittedfrom the drawlu s for the sake of clarity. It is desirable, however, toprovide mechanical means to insure the removal of the chips from thecutters. As shown in Figs. 2 and 20, there are preferably provided twopairs of opposed wire brushes at 95 and 96, one pair of brushes engagingthe sides of cutter 64:, and the other pair of brushes engaging thesides of cutter 65. In actual practice it is usually desirable toprovide an additional set of brushes diametrically opposite those shownin Fig. 2. Iowever, where such brushes are used they are merelyduplicates of those shown and are omitted from Fig. 2 to preventobscuring other parts of the mechanism.

It is realized that the invention may be embodied in, and carried outby, mechanisms other than those particularly disclosed, and hence thepresent disclosure is merely illustrative in compliance with thepatentstatutes and is not to be considered as limiting.

Having thus described my invention, what I claim is 1. A rivet slottingmachine comprising a pair of toothed cutters, and means to hold a pairof rivet blanks to be slotted by the cutters, the relative position ofthe held blanks and the teeth of the cutters causing the cutting ofindividual chips to be made in the two blanks alternately.

2. A slotting machine comprising a memher to be rotated having seats toreceive a plurality of similarly toothed segmental cutters side by side,the seats being in slightly different angular positions to locate therespective teeth of the various cutters in echelon; and similarlytoothed segmental. cutters mounted in said seats.

3. A slotting machine comprising a memher to be rotated having a pair ofseats to receive a pair of similarly toothed segmental cutters side byside, one seat being slightly advanced rotatively with respect to theother seat to locate the teeth of the cutters in staggered relationship;and a pair of similarly toothed segmental cutters mounted in said seats.

4. A slotting machine comprising a main shaft and a secondary shaft,means to feed blanks to a slotting station, means carriedby thesecondary shaft to control the operation of said blank feeding means,blank holding means operable to hold blanks at the slotting station,means carried by the main shaft to control the operation of said "blankholding means, and cutter means carried by the main shaftto slot theblanks.

5. A slotting machine comprising a main shaft and a secondary shaft,means to feed blanks to a slotting station, cams carried by thesecondary shaft to control the operation of said blank feeding means,blank clamping means operable to clamp blanks at the slotting station,cams carried by the main shaft to control the operation of said blankclamping means, and cutter means carried by the main shaft to slot theblanks.

6. A slotting machine comprising a main shaft and a secondary shaft, ablank carrier operable to carry blanks to a slotting station, meansoperable by the secondary shaft to give motion to the blank carrier,spring actuated mechanism operable to feed blanks to the blank carrier,a cam carried by the secondary shaft to control the operation of saidblank feeding mechanism, mechanism operable to clamp blanks at theslotting station, cams carried by the main shaft to control theoperation of said blank clamping mechanism, and cutter means carried bythe main shaft to slot the blanks.

I. A slotting machine comprising a main shaft and a secondary shaft, ablanket carrier operable to carry blanks to a slotting station, meansoperable by the secondary shaft to give motion to the blank carrier,means to feed blanks to the blank carrier, a pair of clamping diesoperable to clamp blanks at the slotting station, a cam carried by themain shaft to move one of said dies into clamping position, spring meansto urge the other of said dies into clamping position, a cam carried bythe main shaft to retract said other die from clamping position, andcutter means carried by the main shaft to slot the blanks.

8. A rivet slotting machine comprising a carrier slotted to receiveshort lengths of individual rivet shanks; means to move the carrierstep-by-st-ep; clamping means operable to clamp a plurality of rivetsfor simultaneous slotting, and means to shift the rivets in the carrierslots to place them in staggered relation when clamped.

9. A rivet slotting machine comprising a rotary shaft; means to hold aplurality of rivets for simultaneous slotting; and a plurality oftoothed segmental cutters mounted side by side on said shaft toindividually slot the respective held rivets, the corresponding teeth ofthe various cutters being positioned in echelon and the cutting edge ofeach tooth of each cutter having a slightly longer radius than thecutting edge of the adjacent preceding tooth on the same cutter asmeasured from the axis of said shaft,

plurality of toothed cutters mounted side by side, the correspondingteeth of the various cutters being positioned in echelon; means tosimultaneously rotate all of the said cutters 10. A rivet slottingmachine comprising a at the same speed; the teeth on each cutter having.different length radii from the cutting edges of said teeth to the axisof rotation of said cutters, said radii gradually lengthening from theforward teeth to the rearward teeth of the same cutter; and means tosimultane- 'ously hold a plurality of rivets for individual slotting byrespective cutters.

11. A rivet slotting machine comprising a rotary shaft, means to hold apair of rivets for simultaneous slotting; and a pair of toothed cuttersmounted side by side on said shaft to individuallyslot the respectiveheld rivets; the teeth of one cutter being staggered With respect to theteeth of the companion cutter and the cutting edge of each tooth of I asingle cutter having a slightly longer radius from that of the adjacentpreceding tooth of the same cutter as measured from the axis of rotationof said shaft.

12. A rivet slotting machine comprising means to hold a pair of rivetsto be slotted, a rotary shaft, a pair of toothed segmental cuttersmounted in parallel planes at right angles to the axis of rotation ofsaid shaft, the teeth of one cutter being staggered With respect to theteeth of the other cutter, the radii of the cutting edges of succeedingteeth on a single cutter as measured from the axis of said shaft beingincreasingly longer for each succeedlng tooth of said single cutter, and7 means to position a pair of rivets for each efiective portion of saidpair of toothed segmental cutters.

13. A rivet slotting machine comprising a rotary shaft, a pair oftoothed cutters mounted side by side 'on said shaft, means to feedrivets to said cutters, and means to hold a pair of rivet blanks to besimultaneously slotted by the cutters, the relative position of the heldblanks and the cutting edges of the teeth of i the cutters causing thecutting of individual chips from the rivet blanks to be made alternatelyfrom said rivet blanks.

14. In a slotting machine, a rotatable dial having a series of blankreceiving recesses,

each successive second period of rest of said dial.

' 15. A slotting machine comprising a rotary cutter head, a main seatformed on said cutter head to support a cutter saw holder, a cutter sawholder having a seat adapted to cooperate with the main seat onthecutter head, said cutter saw holder being provided with partition meansto separate cutter saws mounted thereon, cutter saws mounted in parallelplanes on said cutter saw holder and separated predetermined distancesby said partition means, saw seats on said cutter saw holder for saidcutter saws, means to lock said cutter saws in accurate position on saidcutter saw holder, and means for detachably clamping said cutter sawholder against said main seat on said cutter head, said cutter sawholder being so constructed and arranged that said cutter saws may beaccurately mounted on said cutter saw holder prior to mounting saidcutter saw holder on said rotary cutter head.

EDWIN B. STIMPSON.

